Anodizing is the rapid controlled oxidation of the surface of aluminum. As
electric current is passed through the anodize solution, the surface of an aluminum piece
is converted to a form of its oxide.

TYPES OF ANODIZING PROCESSES:
There are now four types of anodizing referred to as chromic acid anodizing, sulfuric acid
anodizing, hard coat or hard anodizing and PTFE (Teflon) anodizing. Each coating differs
in in their basic properties as well as their end uses.